flask框架json数据的拿取和返回操作示例

}
 "returnCode": "0",
 "returnValue": {
  "A": [
   {
    "id": 3643,
    "parentId": 0,
    "regionName": "阿坝",
    "cityCode": 513200,
    "pinYin": "ABA"
   },
   {
    "id": 3090,
    "parentId": 0,
    "regionName": "阿克苏",
    "cityCode": 652901,
    "pinYin": "AKESU"
   },
   {
    "id": 3632,
    "parentId": 0,
    "regionName": "阿拉善",
    "cityCode": 152900,
    "pinYin": "ALASHAN"
   },
   {
    "id": 899,
    "parentId": 0,
    "regionName": "安康",
    "cityCode": 610900,
    "pinYin": "ANKANG"
   },
   {
    "id": 196,
    "parentId": 0,
    "regionName": "安庆",
    "cityCode": 340800,
    "pinYin": "ANQING"
   },
   {
    "id": 758,
    "parentId": 0,
    "regionName": "鞍山",
    "cityCode": 210300,
    "pinYin": "ANSHAN"
   },
   {
    "id": 388,
    "parentId": 0,
    "regionName": "安顺",
    "cityCode": 520400,
    "pinYin": "ANSHUN"
   },
   {
    "id": 454,
    "parentId": 0,
    "regionName": "安阳",
    "cityCode": 410500,
    "pinYin": "ANYANG"
   }
  ],

from App.ext import db
#定义城市名大写字母类，在数据的最外层
class Letter(db.Model):
  id = db.Column(db.Integer,primary_key =True,autoincrement=True)
  letter = db.Column(db.String(8),unique=True,nullable=False)
#定义城市类，嵌套层
class City(db.Model):
  id = db.Column(db.Integer,primary_key = True,autoincrement = True)
  parentId = db.Column(db.Integer,nullable = False,defaut=0)
  regionName = db.Column(db.String(30),nullable = False)
  cityCode = db.Column(db.Integer)
  pinYin = db.Column(db.String(128))
  #建立外键‘首字母'
  first_letter = db.Column(db.String(8),db.ForeignKey(Letter.letter))

from flask_restful.representations import json
from sqlalchemy.dialects.mysql import pymysql
def add_cities():
#链接数据库
  db = pymysql.Connect(host= '10.0.118.135',user = 'root',password ='xxxxxxx',database = 'tpp6666',port = 3306)
  cursor = db.cursor()
  #读取拿到的数据，遍历数据
  with open('citylist.json')as cl:
    returnValue = json.load(cl).get('returnValue')
    for key in returnValue:
      for city in returnValue.get(key):
         db.begin()
         #插入数据，以每一个大写字母为一个字段插入，以字典的形式
         cursor.execute(
           'insert into city(id,parentId,regionName,cityCode,pinYin,first_letter) values({},{},"{}",{},"{}","{}");'.format(
             city['id'], city['parentId'], city['regionName'], city['cityCode'], city['pinYin'], key))
         db.commit()
if __name__ == '__main__':
  add_cities()

from flask_restful import Resource, fields, marshal_with
from App.models import Letter, City
#字段的格式化：
city_fields = {
  'id': fields.Integer,
  '父编号': fields.Integer(attribute='parentId'),#起别名attribute
  '名称': fields.String(attribute='regionName'),
  '拼音': fields.String(attribute='pinYin'),
  '城市编码': fields.Integer(attribute='cityCode'),
  '首字母': fields.String(attribute='first_letter')
}
value_fields = {
  'A': fields.List(fields.Nested(city_fields)),
  'B': fields.List(fields.Nested(city_fields)),
  'C': fields.List(fields.Nested(city_fields)),
  'D': fields.List(fields.Nested(city_fields)),
  'E': fields.List(fields.Nested(city_fields)),
  'F': fields.List(fields.Nested(city_fields)),
  'G': fields.List(fields.Nested(city_fields)),
  'H': fields.List(fields.Nested(city_fields)),
  'J': fields.List(fields.Nested(city_fields)),
  'K': fields.List(fields.Nested(city_fields)),
  'L': fields.List(fields.Nested(city_fields)),
  'M': fields.List(fields.Nested(city_fields)),
  'N': fields.List(fields.Nested(city_fields)),
  'P': fields.List(fields.Nested(city_fields)),
  'Q': fields.List(fields.Nested(city_fields)),
  'R': fields.List(fields.Nested(city_fields)),
  'S': fields.List(fields.Nested(city_fields)),
  'T': fields.List(fields.Nested(city_fields)),
  'W': fields.List(fields.Nested(city_fields)),
  'X': fields.List(fields.Nested(city_fields)),
  'Y': fields.List(fields.Nested(city_fields)),
  'Z': fields.List(fields.Nested(city_fields)),
}
result_fields = {
  'returnCode': fields.Integer,
  'returnValue': fields.Nested(value_fields)
}
#整体逻辑定义都在这里：
@marshal_with是flask内置的Json序列化的方法，

class CityResrouce(Resource):
  @marshal_with(result_fields)
  def get(self):
    #定义外层字段为空字典{}，存放数据
    returnValue = {}
    # 拿到所有的首字母
    letters = Letter.query.all()
    for letter in letters:
      # 根据首字母拿到每个首字母对应的所有城市
      # filter拿到的结果是一个BaseQuery对象。
      # 如果直接答应BaseQuery对象，它会输出SQL语句
      # 如果想要打印BaseQuery里的所有数据，调用all()方法可以拿到BaseQuery里的所有数据
      cities = City.query.filter(City.first_letter == letter.letter)
      # dict = {letter.letter: cities}
      # print(dict)
      returnValue[letter.letter] = cities.all()
    return {'returnCode': 0, 'returnValue': returnValue}

 

from flask_restful import Api
from App.Apis.CityAPI import CityResrouce
from App.Apis.UserAPI import UerResource
api = Api()
def init_api(app):
  api.init_app(app=app)
api.add_resource(CityResrouce, '/cities/')